Proximity and Tactile Sensor Combining Multiple ToF Sensors and a Self‐Capacitance Proximity and Tactile Sensor

Future labor forces are anticipated to include collaborative robots that work alongside humans in the same environment. Proximity and tactile sensors are among the most important devices for collaborative robots to operate safely. In this paper, we propose a proximity and tactile sensor for a collaborative robot that combines multiple time‐of‐flight (ToF) sensors and a self‐capacitating proximity and tactile sensor. ToF sensors can detect the distance to an object and have a long measurement range. However, at close distances, their detection accuracy deteriorates, and blind spots may likely not be detected. Conversely, the self‐capacitance proximity and tactile sensor detect objects within the blind spots of ToF sensors and contact conditions because the sensor can detect an object before and after contact, being highly sensitive in the proximity range. In the proposed sensor, the electrodes of the self‐capacitance are enlarged, and multiple ToF sensors are used to expand the measurement range and reduce blind spots. A prototype sensor was seamlessly able to measure objects from approximately 400 mm to contact conditions. In addition, the robot arm with the prototype sensor could be controlled in real time using the measured data of the sensor. Therefore, we believe that the proposed sensor can be potentially used as a proximity and tactile sensor for collaborative robots. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.